140 Proof is an advertising company that uses social data from many sources to target relevant ads based on consumers' interests as indicated by their social activity across networks. 140 Proof was launched in 2009 by Jon Elvekrog and John Manoogian III. The company partners with a large number of apps and social networks to use peoples public social network activities to target relevant ads with the blended interest graph. 140 Proof began as an app-based network: its name is a reference to the 140-character limit on Twitter. 140 Proof does not serve ads on the Twitter website itself; instead its API is used by third-party apps to display targeted ads appearing on apps, social sites and mobile networks. Additionally, the service allows advertisers to run campaigns on blogging platforms like WordPress and Tumblr.